Table of Contents
Advertisement
Chapter 2 - RAID
This chapter describes the RAID features which the disk array controller supports.
1. Overview of RAID
1-1. What is RAID (Redundant Array of Inexpensive Disks)?
RAID is an abbreviation for "Redundant Array of Inexpensive Disks". The RAID technology allows more than
one hard disk drive (HDD) to be handled collectively.
In actual, RAID can configure more than one HDD as a single array (logical drive) to operate the HDDs
effectively. This can bring higher performance than a single HDD of a large capacity.
For the array (logical drive) configuration, the host computer recognizes more than one HDD as if it were a
single HDD. The host computer accesses to more than one HDD configuring an array (logical drive) in
parallel.
Some RAID levels can recover data from remaining data and parity by using rebuild feature if an error occurs
in an HDD. This can provide high reliability for the system.
1-2. RAID Levels
The record mode enabling the RAID feature includes several levels. Among the levels, the disk array
controller supports the following levels; RAID 0, RAID 1, RAID 5, and RAID10. The number of HDDs required
to create a logical drive varies depending on the RAID level as shown in the table below.
RAID level
RAID 0
RAID 1
RAID 5
RAID 10
For details of the RAID levels, see "2. RAID Levels" described later in this
chapter.
Tips
Number of required HDDs
Min.
Max.
1
4
2
2
3
4
4
4
27
Advertisement
Table of Contents
